U.S. Climate Monitoring
National Overview

May 2005

• May temperatures were below average for most of the eastern part of the nation and slightly above average for the western U.S. For information on temperature records during the month, please go to NCDC's Extremes page
• The precipitation signal was near average for the nation with conditions being wetter than average in the West and far Northeast and remaining generally drier than average in the Mississippi Valley through the Great Lakes and parts of the Northeast. For more information on drought during May, please visit the U.S. Drought page.

• Spring temperatures were above average for the U.S. with below average temperatures for most of the eastern part of the nation and above average for the western U.S. For information on temperature records during the season, please go to NCDC's Extremes page
• The precipitation signal was near average for the nation with conditions being wetter than average in the West and Northeast and remaining generally drier than average from the South, through the Mississippi Valley and across the Great Lakes. For more information on drought during spring, please visit the U.S. Drought page.
  
  
  
• Indices used to determine the state of ENSO suggest that the Equatorial Pacific is transitioning from a weak warm phase (El Niño), to ENSO neutral conditions. Sea Surface Temperatures were slightly above normal across the central and western equatorial Pacific during May, though with somewhat weaker positive anomalies than in previous months. To see the latest NOAA advisory and typical impacts of a La Niña or El Niño episode for the U.S., go to NOAA's Climate Prediction Center.

• May 2005 ranked as the 48th coldest May in the 1895 to present record. The preliminary nationally averaged temperature was 60.7°F (15.9°C), which was 0.4°F (0.2°C) below the long-term mean.
• May 2005 had near average precipitation, nationally, ranking 49th driest.
• March-May temperature was above average and ranked as the 35th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature for March-May was 52.4°F (11.3°C) which was 0.5°F (0.3°C) above the long-term mean.
• March-May had near average precipitation, ranking 57th driest in the last 111 years.
• The June 2004-May 2005 temperature was above average and ranked as the 20th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature was 53.7°F (12.1°C) which was 0.9°F (0.5°C) above the long-term mean.
• Precipitation was much above average for June-May, ranking 5th wettest for the last 12 months based on a record of 110 such periods.

• May 2005 temperatures ranked much below average for 10 states. A further 12 states in the contiguous U.S. had below average temperature while 9 states were warmer than average for the month.
• Alaska temperatures were record warmest for May with a statewide temperature of 5.6°F (3.1°C) above the 1971-2000 mean - the first time the May anomaly has been higher than 5.0°F in recorded history. Spring temperatures were also warmer than average ranking 2nd since 1918 with an anomaly of 5.0°F (2.8°C).
• May was wetter than average for many western states and parts of the Northeast, while the Mississippi Valley and Great Lakes across to the Northeast was mostly drier than average. Five states had much above average precipitation statewide, including Oregon, which had its 2nd wettest May on record, and 6 states had much less precipitation than the long-term mean.
  
• The 3 month period, March-May, was warmer than average for much of the West while much of the eastern seaboard was colder than average.
• March-May 2005 was much wetter than average for 8 states. Seven states were much drier than average.
• June-May 2005 was warmer than average for much of the nation. Only 2 states were significantly cooler than average over the last 12 months.
• The last 12 months were much wetter than average for much of the nation, with Nevada having its wettest June-May on record.

  See NCDC's Monthly Extremes web-page for weather and climate records for the month of May.